Subjective well-being (SWB) has been a core subject in psychological and social gerontology since the 1950's. It refers to people's evaluations of their lives, which involve cognitive assessment, positive affect, and negative affect. From a life course perspective, we propose to analyze how SWB unfolds in old age among black, Hispanic, and white Americans. We have four specific aims: (a) to depict quantitatively the overall trajectory or age norm of intrapersonal changes in SWB from age 60 up to the 90's, (b) to examine the heterogeneity underlying the age norm of SWB, (c) to assess the relative importance of psychological resources (i.e., control and self-esteem) and life circumstances (i.e., social relations, financial status, and health status) in influencing the age norms of SWB and their sub-trajectories, and (d) to analyze the direct, indirect, and interaction effects of ethnicity on the age norms and sub-trajectories of SWB. To accomplish the above specific aims, we propose to analyze data from nine longitudinal studies of older Americans. The analytical strategies will include a combination of multi-level analysis, cluster analysis, multinomial logit analysis, and structural equation modeling.